Method of making bumpers



fiepft. 6, W49. J. H. BRAZIL METHOD OF MAKING BUMPERS filed June' so, 1948 Y INVENTOR. \jo 7? H ,5 razzz Patented Sept. 6, 1949 METHOD OF MAKING BUMPERS John H. Brazil, Highland Park, Mich; assignor to Chrysler Corporation, Highland Park, Michqa corporation of Delaware Application June 30, 1948, Serial No. 36,141

7 Claims.

This application is a continuation-in-part of Brazil copending application, Serial No. 644,555, filed January 31, 1946, now abandoned.

This invention relates to a method of forming articles such as bumpers suitable for use on automotive vehicles. More specifically it relates to a method of forming bumpers havin a bent or concavo-convex cross section and end portions extending .at substantial angles to the main body portions of the bumpers.

The manufacture of bumpers of the above de scription presents many problems because of the inherent difliculties in providing lengthwise bends in metallic strips having a bent or concave-convex cross section. Wrinkles may easily form at these lengthwise bends, which are removable with great difficulty if at all. Moreover, it is a problem to polish the exterior of a bumper of the above description with a satisfactory minimum of cost and time.

An object of the present invention is to provide improvements in the manufacture of articles such as automobile bumpers having lengthwise bends such that end portions are provided extending at substantial angles to the bod portions. These improvements in manufacture are employed to great advantage with bumpers having a bent or concavo-convex cross section.

' A further object is to improve a process of manufacture of articles such as bumpers having lengthwise bends and bent cross section if desired by performing a polishing operation included in the process of manufacture at the appropriate time with respect to other steps in the process of manufacture so that the polishing operation involves a satisfactory minimum of cost and time.

Other objects will appear from the disclosure.

In the drawing:

Fig. 1 isa perspective view of a metallic strip upon which the process of manufacture of the present invention is performed;

Fig. 2 shows a pair of rolls through which the strip of Fig. 1 is passed;

Fig. 3 is a sectional view of the rolls taken on the line 3-3 of Fig. 2;

Fig. 4 is a partial view of the strip of Fig. 1 bent to oblong rectangular shape and ready to be Welded;

Fig. -5 is a view ofthe bentstrip of Fig. 4 after Welding and during the polishing operation;

Fig. 6 is an end view of the bent strip showing how the strip is cut; and f Fig. 7 is a perspective View of a completed bumper formed from the aforementioned bent strip,

The reference character Ifldesignates a fiat metallic strip shown in Fig. 1. The'strip II! is passed between a pair of complementary rolls I I and I2 as shown in Figs. 2 and 3. The rolls change the cross section of the strip so that the cross section instead of being straight as in Fig. 1, is in a'general sense bent or more specifically compound concave-convex. Supplementary means operate upon the strip I!) either after or as it passes through the rolls' H and I 2 so as to transform-it into anoblong rectangle having round corners. This oblong rectangle, illustrated in Fig. 4, is designated by the reference character I 4, and the aforementioned round corners thereof are designatedby the reference character I5. A gap I6 in one short side of "the oblong rectangle I4 isforme'd by the ends of the strip. "The ends are now welded or otherwise bonded,"as indicated at I! in Fig.5, to preferably form as shown a substantially smooth joint. Thereupon the welded or bonded oblong rectangle I4 is subjected to a polishing operation illustrated in Fig. 5. The rectangle I 4 may be suitably mounted upon a rotating turntable 22 for rotation 'therewith'and its outer surface is subjected to the action of a plurality of rotating polishing brushes, only one of which is shown, abrush I8. The turntable may be driven by a motor 24 through worm gearing 26 and may be provided with fixed and adjustable clamping members 28 and 30 respectively for holding the rectangle I4 by its inner surface 'and with a cam track 32'paralleling the outer periphery of the rectangle'I- l. The brushes may be suitably mounted on hinged arms 33, each carrying a motor for rotating the brush. Each arm has a follower roller 36 which is biased by'a spring 38 into constant contact with the track 32 such that the brushes maybe urged toward the center of rotation of the rectangle I4 and to move toward and away from 'the' center of rotation as they contact different portions of 'theexterior of the rectangle at different distances from the center of rotationto thus provide uniform polishing. After the exterior of the rectangle I4 'has'been sufliciently polished; the rectangle is removed from the rotating holder and is cut into two bumpers l9 by a cut at the weld l1 and by corresponding cuts at the opposite short side of the rectangle. Either simultaneously with the cutting operation or subsequently thereto the ends of the bumpers H) are given a curved contour, as indicated at 20 in Fig. 6. The ends are also shaped transversely, as indicated at 2| in Fig. 7, so as to be bent slightly toward one another. As seen in Fig. 7, each of the two bumpers has ends that extend at substantial angles to the main body portion thereof and so is of shallow U-shape and of bent cross section, or. more specifically, concave-convex section.

The advantage in forming the straight strip of Fig. 1 to oblong rectangular shape and bent cross section of Fig. 4 before welding is that the rounded corners l5 are most easily shaped with a minimum of wrinkling and distortion. The advantage in polishing the oblong rectangle M with the ends welded, as shown in Fig. 5, is that the rectangle may be held by the interior of the rectangle alone, and therefore, the polishing operation may be carried out with a minimumi'of time,

trouble, and expense.

I claim:

1. A method of making automobile bumpers consisting in mounting a rectangular metallic annulus member having continuous inner and outer surfaces and a bonded joint substantially midway a short side thereof on a holding element by its inner surface only, polishing the contiguous portions of said continuous outersurface with a rotary brush while so held, during said polishing continuously adjusting the relative positions of the brush and the said outer surface of the member to maintain a substantially uniform relationship therebetween whereby to uniformly polish the said contiguous portions and thereafter severing said member at the bonded joint and at the short side of the member opposite the joint to produce two bumpers.

2. A method of making automobile bumpers comprising rolling a substantially flat strip of metallic stock to fashion the same transversely with a predetermined section, longitudinally fashioning the strip into a generally oblong rectangular annulus member having aligned opposite return bend sections in a short side thereof and having the free ends of said sections in juxtaposition, the opposite sidesof said strip providing inner and outer surfaces of said member, securing said rectangular member by its inner surface only on a holding element, polishing the contiguous portions of the outer surface of said member with a rotary brush while so held, during polishing effecting relative movement between the brush'and said outer surface whereby to polish said contiguous portions and effecting relative movement between the brush and said holding element to maintain a substantially uniform relationship between said brush and outer surface whereby to substantially uniformly polish the said contiguous portions, and thereafter dividing said member into two bumpers through the short sides of the rectangle;

3. A method of making automobile bumpers comprising rolling a flat strip of metallic stock to fashion the same transversely with a predetermined section, longitudinally fashioning the strip into a generally oblong rectangular annulus member having aligned opposite return bend sections in a short side thereof and having the free ends of said sections in juxtaposition, the opposite sides of said strip providing inner andouter surfaces of said member, bonding the said free ends of said sections to each other to form a continuous member, securing said member by its inner surface only on a rotatable holding element, rotating said member and element, continuously polishing the outer surface of said member with a rotary brush while the member is rotated, during polishing continuously adjusting the position of the brush relative to the outer surface of the member to maintain a uniform relationship therebetween, and thereafter severing said member at the bond and at the short side of the member opposite the bond to produce two bumpers.

l. A method of making automobile bumpers comprising rolling a flat strip of metallic stock to fashion the same transversely with a predetermined section, longitudinally fashioning the strip into a generally oblong rectangular annulus member having aligned opposite return bend sections in a shortside thereof and having the free ends of said sections in juxtaposition, the opposite sides of said strip providing inner and outer surfaces of said member, bonding the said free ends of said sections to each other to form a continuous member, securing said member by its inner surface only on a holding element, rotating the held member, polishing the outer surface of the member with a rotatable brush while the member is rotating, during polishing moving the brush relative to the center of rotation of the member to accommodate the changing distance of the different portions of the exterior of the member from said center of rotation whereby to continuously contact the said exterior portions, and thereafter severing said member at the bond and at the short side of the member opposite the bond to produce two bumpers.

5. A method of making automobile bumpers comprising rolling a fiat strip of metallic stock to fashion the same transversely with a predetermined section, longitudinally fashioning the strip into a generally oblong rectangular annulus member having aligned opposite return bend sections in a short side thereof and having the free ends of said section in juxtaposition, bonding the said free ends of said sections to each other to form a continuous member, securing said member by its inner surface only on a holding element, rotating said held member, polishing the outer surface of the member while so held and rotated with a rotary brush, during polishing effecting relative movement between the brush and member to accommodate the changing distance of the different portions of the exterior of the member from the center of rotation thereof whereby to continuously contact the said exterior portions of the member as they are presented to said rotating brush, and thereafter severing said member at the bond and at the short side of the member opposite the bond to produce two bumpers.

6. A method of making automobile bumpers comprising forming a ribbon-like steel strip into an oblong rectangular annulus having round corners and a gap in one short side formed by the free ends of the strip, bonding the free ends to form a substantially smooth continuous inner and outer surface on the annulus, securing the annulus by its inner surface only on a rotatable holding element, rotating the annulus, polishing the entire outer surface of the annulus with a rotary brush while the annulus is so held and rotated, during polishing continuously moving the brush relative to the center of rotation of the member to accommodate the changing distance of the different portions of the exterior of the mem- 5 6 her from said center of rotation as they are presented to said brush whereby to substantially REFERENCES CITED uniformly contact said exterior portions, and then The following references a e of co d in the cutting the annulus at the bond and at the short file f t s patent: side of the annulus opposite the bond while simul- UNITED STATES PATENTS taneously prov1d1ng the cut ends with a curved contour to produce two bumpers. Number Name Date 7. A method as claimed in claim 2 wherein the 1,323,212 pp Oc 1931 fiat strip is fashioned transversely into a com- 1,865,570 Kellogg July 5, 1932 pound concave-convex section. 10 ,130 Harrison Mar. 27, 1934 JOHN H. BRAZIL. 1, 6 ,453 Lyon July 17, 1934 1,966,723 Ireland July 17, 1934 2,166,859 Carlson July 18, 1939 2,299,121 Amsden Oct. 20, 1942 

